ITV, the U.K. station that produces popular drama
"Downton Abbey," has released some details about the upcoming two-hour Season 4 Christmas special. Don't keep reading if you don't want to be spoiled.

It may be Christmas Day when the episode airs, but it won't be Christmas during the episode. It's actually the summer season and the Crawley family will head to London for Rose's coming out.

Viewers will get to see the Crawleys' impressive London residence, Grantham House, for the first time and will also be treated to "Buckingham Palace" (though the show did not film at the real palace).

There will be a series of galas and parties as Lady Rose is presented to society, while a scandal will threaten to engulf the British monarchy and Robert will be forced to act to protect both the royal family and his own.

Intrigue!

In addition to already-announced guest stars
Shirley MacLaine and
Paul Giamatti as Cora's mother and brother, the episode will also feature
James Fox as Lord Aysgarth,
Guy Williams as King George V (the grandfather to reigning Queen Elizabeth II) and
Oliver Dimsdale as the Prince of Wales (Edward VIII, Queen Elizabeth's uncle).

The "Downton Abbey" Christmas special will air Wednesday, Dec. 25 in the U.K., while the full Season 4 will begin airing in the U.S. on Sunday, Jan. 5, 2014.